Drill bit



ept 2 1962 J. H. EDWARDS DRILL BIT 3 Sheets-Sheet 1 Filed May 31, 1960ZIQ Vm mi Ma A IIIILIIILI Ill {IN s .H llllilllalll JCK H Sept. 25, 1962Filed May 31, 1960 TRl-CONE BIT 3 s J. H. EDWARDS 3,055,443

DRILL BIT 3 Sheets-Sheet 2 IN VENTOR, JACK H. EDWARDS.

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Se t. 25, 1962 J. H. EDWARDS w il rum/10a JACK H. EDWARDS, BY

3,055,443 DRILL BIT Jaclr I-I. Edwards, Houston, Tex., assignor, bymesne assignments, to Jersey Production Research Company, Tulsa, Okla.,a corporation of Delaware Filed May 31, 1960, Ser. No. 32,823 7 Claims.(Cl. 175-330) The present invention is directed to a drill bit fordrilling a well bore. More particularly, the invention is concerned witha drill bit provided with abrasive-resistant material on a cutting edge.In its more specific aspects, the invention is concerned with acombination drill bit embodying a cutting edge and coaxial drillingmeans.

The present invention may be briefly described as a drill bit whichcomprises a hollow body member having preferably an annular cutting edgeon a free end and adapted to be connected to a hollow drill string onits other end. The cutting edge is preferably provided withabrasiveresistant means for drilling through subsurface earth formationswhich ordinarily rapidly erode usual metallic surfaces. Arranged withinand attached to the hollow body member is a rotatable drilling meanswhich assist in drilling operations in penetrating the dense earthformations. The hollow body member is provided with means adapted todeliver drilling fluid separately to the cutting edge and to therotatable drilling means. The hollow body member forms a shroud whichencloses the rotatable drilling means and a window is provided in thewall of the hollow body member for discharge of rock cuttings from therotatable drilling means to the outside of the shroud.

'When drilling rock with the usual rock bit such as a multicone bit, thefracture effect of loading on the teeth of the rock bit is limited dueto the rock matrix surrounding the borehole. Failure of rock isprevented in a large degree by the restraint to movement ofiered by thesurrounding rock. Thus, it appears that in usual drilling operationssmall cracks are created in the rock which return to the surface of thebottom of the well bore creating chips instead of propagating deep intothe rock itself. Thus, the bit tooth of the usual rock bit presses onthe rock surface, tending to create small cracks which propagatedownward but by virtue of the resistance to fracture offered by thesurrounding rock matrix, the crack follows the path of least resistanceand emerges at the surface on the bottom of the well bore, thus creatingthe small chips. In the practice of the present invention, theresistance of the rock to fracture is removed or reduced by employing animproved drill bit which destroys the rock rapidly and efficiently. Byvirtue of providing a hollow cylindrical body having a cutting edge onits lower end and provided with abrasive-resisting material such asdiamonds, metal car bides, such as tungsten carbide, boron carbide,titanium carbide, titanium-tungsten carbide, columbium-tantalumtitaniumcarbide, metal alloys, and cemented carbides known to those schooled incutting tool manufacture, and the like, the cylinder cuts a smallannular portion of the rock, forming a core which is received within thehollow body member. By arranging within the hollow body membervertically spaced from. the cutting edge a drilling means such as amulticone rock bit, it is possible to drill out the core rapidly andefliciently in that the core is no longer laterally restrained. Thus, bycombining a cutting edge on a cylindrical member with a rock bit ordrilling means enclosed and shrouded by the cylindrical member, it ispossible to drill rapidly and efficiently.

In the practice of the present invention, it is necessary to provide ameans for egress of the chips formed by destruction of the core.Otherwise, these chips would have to fall to the bottom of the well andbe ground substantially to a powder by the annular cutting edge. ThisPatented Sept. 25, 1962 ice would result in loss of efiiciency andgrinding away of material which has already been removed from the bottomof the well. In order to prevent this inefficient result, in the drillbit of the present invention, one or more windows are provided in theshroud adjacent the drilling means for drilling out the core such thatthe large chips or fragments of the rock formed by destruction of thecore are discharged from the inner drilling means to the outside of theshroud to be caught up by and carried to the earths surface withdrilling fluid which may be gaseous or liquid drilling fluid suppliedseparately to the cutting edge and to the inner drilling means in thedevice of the present invention.

The present invention will be further illustrated by reference to thedrawing in which:

FIG. 1 is an elevational view of one embodiment of the presentinvention;

FIG. 2 is a sectional view of the embodiment of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 3 illustrating a tricone cutting means;

FIG. 5 is a partial sectional View of a preferred embodiment of thepresent invention illustrating the construction thereof;

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5; and

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 5.

Referring now to FIGS. 1, 2, and 3 of the drawing, numeral 11 designatesa hollow body member providing a space 12. The hollow body member 1-1 isprovided with threaded means 13 on its upper end in the form of theusual pin for attachment to the lower end of a hollow drill string. Thehollow body member 11 is provided with windows 14 for discharge ofcuttings from the interior space 12 to the exterior of the hollow bodymember 11.

The lower free end of the hollow body member 11 is provided with acutting edge 15 in the form of a matrix 16 in which there is embedded orarranged abrasiveresistant materials such as diamonds, tungsten carbide,and the like. Diamonds and metal carbides may be used simultaneously, ifdesired.

Arranged within the space 12 and rotatably attached to the hollow bodymember 11 are cone cutters 17 which are arranged on spindles 18 attachedto the body member 11. Drilling fluid is discharged into the hollow bodymember 11 by means of a passage 19 which connects to the hollow drillstring, not shown. This drilling fluid is discharged separately to thecutting edge 15 by fluid passageways 20 and to the conical cutters 17 bypassageways 21.

Wherein FIG. 3 illustrates a 2-cone bit arranged in the space v12, FIG.4 shows the arrangement of a tn'cone bit.

Referring now to FIGS. 5, 6, and 7, a drill bit in accordance with thepresent invention is comprised of a hollow body member 30 having a freeend 31 which is provided with a matrix containing abrasive-resistantmaterial 32 such as diamonds and/or metal carbides and the like. Thehollow 'body member 30 is provided with a threaded pin 33 for threadedlyattaching the hollow body member 30 to the lower end of a drill string,not shown. The hollow body member 30 is provided with a plurality ofports or windows 34 which may be 3 in number spaced apart Arrangedwithin the space 35 enclosed by the hollow body member 30 is a triconerock bit 36 which is threadedly attached by a sleeve 37 to the hollowbody member 30. The sleeve 37 is provided with radial ports 38 whichcommunicate with an 3 annular space 39 which serve to discharge drillingfluid on bottom through the free end 31 of the hollow body member fromthe passageway 40 which communicates with the hollow drill string towhich the hollow body member 30 is connected by threaded pin 33.

A plate member 41 is threadedly connected to the sleeve 37 and isprovided with fluid passageway 42 which communicates with a space 43 andwith ports 44 which serve to discharge drilling fluid to the triconerock bit 36, the tricone rock bit 36 being attached to the sleeve 37 bymember 45 which, in turn, is welded to an adapter ring or plate 46.

The hollow body member 30 is provided with splines 47 whichcooperatively engage with centering lugs 49 of an annular member 48 tomaintain the tricone rock bit 36 coaxially with the hollow body member30. The body 30 and annular member 48 are slotted to receive rectangularshaped window frames 50 which form windows 34 for the passage of fluidsand cuttings from the space 35 to the exterior of the body 30. The body30 and member 48 together form vertical passages 51 for the flow offluid to the underside of the lower end 31 of body member 30.

The free end 31, forming the lower end of body member 30, is threadedlyattached to the body by mating threads 52, as shown, and is welded tothe body member 30 as at 53 and to annular member 48 as at 54. The end31 of body 30 is provided with spaced-apart vertical passageways 55which fluidly communicate the lower end of the body 30 with the passages51, annular space 39, ports 38 and passageway 40.

From the description and the several figures of the drawing, it isapparent that the passageways 21 and ports 44 discharge above andbetween the rotatable drilling means and are parallel to thelongitudinal axis of the hollow body member, the passageways 21 andports 44 being of constant diameter. Likewise, it is also manifest fromthe drawing that the openings through the wall of the shroud forming thewindows 14 and 34 are at the same level as the level of the rotatabledrilling means.

In the several embodiments, the longitudinal axes of the inner drillingmeans intersect the longitudinal axis of the hollow body member at acommon point.

Thus, it will be seen from the description taken with the drawing andespecially with reference to FIGS. 5, 6, and 7 that the drilling deviceof the present invention is easily constructed and is of durable nature.

In operating the device of the present invention, the drilling device isconnected to the lower end of a hollow drill string which is rotated. Byvirtue of the abrasiveresistaut material on the cutting edge, an annulargroove is cut causing the hollow body member to enclose a core which isthen contacted by the rotating inner rock bit or drilling means causingthe destruction thereof and the formation of large chips which areflushed by the drilling fluid through the ports or windows 34 and outinto the ascending stream of drilling fluid which flows downwardlythrough the passageways 4t) and upwardly in the annulus between thedrill string and the wall of the borehole.

In order to illustrate the practice of the present invention, a drillingbit was constructed in accordance with the present invention andprovided with windows and having diamonds on its lower free end forminga cutting edge. As a result of drilling operations in Indiana limestonewhile circulating water as the drilling fluid, drilling rates of 14 to15 feet per hour were obtained. In comparative operations with aconventional rock bit, drilling rates of about feet per hour wereobtained.

In drilling operations in Carthage marble, substantial improvements wereachieved in the drill bit of the present invention as compared to theconventional rock bit.

In employing the drill bit of the present invention in drillingsandstone, drilling rates of to 18.5 feet per hour were obtained whereasin rock bits of the conventional type, the drilling rate was from about8.7 to 10 feet per hour.

To illustrate the effect of drilling unrestrained rock, the coreresulting from these drilling operations was drilled at a rate 2- to3-fold the rate achieved with the conventional rock bit in restrainedrock such as at the bottom of a hole. In other words, the practice ofthe present invention allows the achievement of rapid drilling since themajor portion of the rock is placed in an unrestrained condition whichallows it to be rapidly drilled out. The present invention is thereforequite important and useful.

The nature and objects of the present invention having been completelydescribed and illustrated, what I wish to claim as new and useful andsecure by Letters Patent is:

l. A drill bit which comprises a hollow body member having a cuttingedge on a free end and adapted to be connected to a hollow drill stringon its other end, a plurality of drilling means attachedly arrangedwithin said hollow body member for rotation relative to said bodymember, the longitudinal axes of said drilling means intersecting thelongitudinal axis of said body member at a common point, and means insaid hollow body member adapted to deliver drilling fluid separately tosaid cutting edge and to said rotatable drilling means, said meansadapted to deliver drilling fluid forming separate passagewaysdischarging separately above and between said drilling means and throughsaid cutting edge, the passageways discharging above and between saiddrilling means being parallel to the longitudinal axis of said bodymember and having a constant diameter throughout the length thereof,said hollow body member forming a shroud enclosing said rotatabledrilling means and having a window in its wall adjacent said drillingmeans, said window being formed for lateral discharge of cuttings fromsaid rotatable drilling means to the outside of the shroud, said windowbeing formed by an opening through the wall of said shroud at the samelevel as the level of said rotatable drilling means in said shroud.

2. A drill bit in accordance with claim 1 in which the drilling means isa tricone rock bit.

3. A drill bit which comprises a hollow body member having a cuttingedge on a free end and adapted to be connected to a hollow drill stringon its other end, abrasive-resistant means on said cutting edge, aplurality of drilling means attachedly arranged within said hollow bodymember for rotation relative to said body member, the longitudinal axesof said drilling means intersecting the longitudinal axis of said bodymember at a common point, and means in said hollow body member adaptedto deliver drilling fluid separately to said cutting edge and to saidrotatable drilling means, said means adapted to deliver drilling fluidforming separate passageways discharging separately above and betweensaid drilling means and through said cutting edge, the passagewaysdischarging above and between said drilling means being parallel to thelongitudinal axis of the body member and having a constant diameterthroughout the length thereof, said hollow body member forming a shroudenclosing said rotatable drilling means and having a window in its walladjacent said rotatable drilling means, said window being formed forlateral discharge of said outtings from said rotatable drilling means tothe outside of said shroud, said window being formed by an openingthrough the wall of said shroud at the same level as the level of saidrotatable drilling means in said shroud.

4. A .drill bit in accordance with claim 3 in which theabrasive-resistant means comprises diamonds.

5. A drill bit in accordance with claim 3 in which theabrasive-resistant means comprises metal carbide.

6. A drill bit in accordance with claim 3 in which theabrasive-resistant means comprises tungsten carbide.

7. A drill bit which comprises a hollow body member having an annularcutting edge on a free end and adapted to be connected to a hollow drillstring on its other end, abrasive-resistant means on said cutting edge,a plurality of drilling means attachedly arranged within said hollowbody member for rotation relative to said body member, the longitudinalaxes of said drilling means intersecting the longitudinal axis of saidbody member at a common point, and means in said hollow body memberadapted to deliver drilling fluid separately to said cutting edge and tosaid rotatable drilling means, said means adapted to deliver drillingfluid forming separate passageways discharging separately above andbetween said drilling means and through said cutting edge, thepassageways discharging above and between said drilling means beingparallel to the longitudinal axis of the body member and having aconstant diameter throughout the length thereof, said hollow body memberforming a shroud enclosing said rotatable drilling means and having awindow in its Wall adjacent said rotatable 6 drilling means, said windowbeing formed for lateral discharge of cuttings from said rotatabledrilling means to the outside of said shroud, said window being formedby an opening through the wall of said shroud at the same level as thelevel of said rotatable drilling means in said shroud.

References Cited in the file of this patent UNITED STATES PATENTS839,837 Guttzeit Jan. 1, 1907 2,022,101 Wright Nov. 26, 1935 2,034,073Wright Mar. 17, 1936 2,587,429 Arutunofi Feb. 26, 1952 2,667,334 OrtloflJan. 26, 1954 2,708,103 Williams May 10, 1955 2,738,166 Koch Mar. 13,1956 2,854,219 MacNeil Sept. 30, 1958 2,975,849 Stuart Mar. 21, 1961UNITED STATES PATENT OFFICE CERTIFICATE QT CORRECTIN Patent N00 s ossaae September 25, 1962 Jack H. Edwards hat error appears in the abovenumbered pat=- It is hereby certified t hat the said Letters Patentshould read as ent requiring correction and t corrected below.

In the drawings Sheet 2 FIG, 5, part 36 thereof for "TRI-CONE BIT read eTHREE CONE BIT column 2 lines 21,- 55 and ()9 column 3, lines 9 and 15and column 4, line 41, for 'tricone" read three cone u Signed and sealedthis 12th day of March 1963 EAL) Atte t:

' DAVID L. LADD Commissioner of Patents ESTON Go JOHNSON AttestingOfficer

